PRELIMINARY PUBLIC HEALTH ASSESSMENT
CRATER RESOURCES/KEYSTONE COKE/ALAN WOOD
KING OF PRUSSIA, MONTGOMERY COUNTY, PENNSYLVANIA
The tables in Appendix B list the contaminants of concern. PADOH evaluates these contaminants in the following sections of the public health assessment and determine whether exposure to them has public health significance. PADOH selects and discusses these contaminants based upon several factors, including (a) concentration of chemicals on site and off site, (b) comparison of on-site and off-site concentrations with public health assessment comparison values for carcinogenic and non-carcinogenic endpoints, (c) community health concerns, and (d) field and laboratory data quality.
In the data tables presented in Appendix B, the fact that a contaminant is listed does not mean that it will cause adverse health effects from exposure. Instead, the list indicates which contaminants will be evaluated further in the public health assessment.
Comparison values for public health assessments are contaminant concentrations in specific environmental media (air, water, soil, etc.) that are used to select contaminants for further evaluation. These values include Environmental Media Evaluation Guides (EMEGs), Reference Dose Environmental Media Guides (RMEGs), Cancer Risk Evaluation Guides (CREGs), and other relevant guidelines. EMEGs do not consider carcinogenic effects and are derived from ATSDR's Minimal Risk Levels (MRLs). RMEGs also consider noncancer health effects, but are derived using EPA's Reference Dose (RfD). Both MRLs and RfDs are estimates of daily exposure to a chemical considered unlikely to cause noncancer adverse health effects. CREGs are estimated contaminant concentrations based on a one excess cancer in a million persons exposed over a lifetime (70 years). CREGs are calculated from EPA's cancer slope factors.
We conducted a search of the EPA Toxic Chemical Release Inventory (TRI) for the site and local area for 1987, 1988 and 1989. The Henderson Road and Stanley Kessler Superfund sites are within one mile northwest of Crater Resources. All three sites have released volatile organic compounds into groundwater and soils. Crater Resources and Henderson Road are also contaminated with heavy metals (2).
A. On-Site Contamination
No accurate records of on-site monitoring well locations or construction details have been given to PADOH or ATSDR. In May 1983, FIT conducted a site inspection and collected groundwater samples from two existing on-site wells. However, in 1989, FIT could not locate the wells (1). Consequently, when a second round of sampling was performed in June 1990, no on-site groundwater samples were collected. As stated in the Site Visit section, no on-site wells could be found by PADOH and others who toured the site in November 1992. An obvious and serious data gap exists with respect to on-site groundwater.
Table 1 (Appendix B) reports the maximum concentrations of contaminants present above comparison values in on-site groundwater from samples collected in 1983.
Soil and Sediment
Only two soil samples were collected in the 1990 sampling round. Neither contained contaminants above background levels or comparison values. Considering the presence of uncovered waste material present on site, two soil samples are not adequate to characterize on-site soils, especially surface soil. No soil samples were collected in 1983.
Sediment samples were collected in 1983 (four) and 1990 (one). Figures 4 and 5 show schematically the approximate locations of sediment sampling. No accurately scaled map of the site has been given to PADOH and none may, in fact, exist. The reader should also note that the two site sketches use different numbering sequences to identify lagoons and ponded areas.
Table 2 summarizes the contaminants found at levels above comparison values in on-site sediment.
Surface water bodies on site consist of small ponds in quarries, sink holes, or other excavations. No perennial streams flow through the site; however, an intermittent stream drains part of the site east of the limestone quarry. Cyanide (at 2,400 ppb) is the only contaminant of concern reported in on-site surface water from samples collected in 1983. Only one surface water sample was collected in 1990. It was taken at a different location from the 1983 samples and, among the contaminants of concern, showed only low levels of cadmium (5.9 ppb) and cyanide (18.8 ppb) (1). Because of the scarcity of samples and the time interval between them (seven years), PADOH and ATSDR do not believe a representative description of surface water exists for this site.
Contaminants in ambient air were either not detected or not reported in documents reviewed by PADOH. The extent of air sampling, if any, is uncertain. Instruments designed to detect volatile compounds (OVA, h-NU) were apparently used during the investigation (1990), but no readings above background were reported except at auger borings into the actual waste (1). The ability of these instruments to detect small amounts of VOCs is poor.
Solid Waste Analysis
Three waste samples ("tar") were collected, one from borehole cuttings at quarry 1 and two from hand-augered locations in quarry 3 (Figure 5). The samples were analyzed for a wide range of chemicals including volatiles, metals, and pesticides. Elevated levels of several compounds were detected including naphthalene (15,000 ppm), dibenzofuran (1,100 ppm), benzene (6 ppm), benzo(a)pyrene (990 ppm), and pyrene (2,300 ppm). The depth of the auger borings is uncertain; however, "tar" is also visible along quarry walls in several locations on site.
B. Off-Site Contamination
Only one off-site monitoring well (monitoring well 5) was drilled (Figure 3). This well was obstructed during the June 1990 sampling round, so only the 1983 data are available.
One off-site irrigation well, about 400 feet west of monitoring well 5, has been impacted by site-related contaminants. This well also supplies a small pond (one acre) within which a fountain, through a timing device, shoots jets of water some 50 feet into the air for decorative purposes. The fountain operates for about three hours each day. Table 3 reports the maximum contaminant levels for the affected irrigation well and monitoring well 5. The irrigation well also contained benzene at 27 ppb (1).
Eight private (residential) wells have been identified within 1.5 miles of the site. None are within the expected groundwater flow path from the site, and all are free of contaminants. No other private, industrial, or irrigation wells are known to be downgradient of the site.
All other residences and businesses in the area are served by public water supplies, the most significant of which is the Philadelphia Suburban Water Company. The Upper Merion Reservoir is the major contributor to this water system in the area of the site. According to reports received and reviewed by PADOH, the reservoir contains low levels (5 ppb) of trichloroethene (TCE), a compound not yet attributed to Crater Resources. It is unlikely, however, that the reservoir has received site contaminants. This is because the reservoir is over one mile northwest of the site while groundwater flow is believed to be eastward from the site toward a pumping well and the Schuylkill River. The contaminants in the Upper Merion Reservoir are more likely coming from other hazardous waste sites closer (one-half mile) than Crater Resources and within the cone of depression created by reservoir pumping. A properly designed monitoring well network will be necessary to test this hypothesis.
C. Quality Assurance and Quality Control
In preparing this public health assessment, ATSDR and PADOH rely on the information provided in the referenced documents. We assume that adequate quality assurance and quality control measures were followed regarding chain-of-custody, laboratory procedures, and data reporting. The analyses, conclusions, and recommendations in this public health assessment are valid only if the referenced documents are complete and reliable.
In the case of Crater Resources, ATSDR and PADOH do not consider the sampling results to be adequate or representative of site conditions, especially with respect to groundwater. Too few samples are available for all media, and the time interval over which sampling was conducted is more than a decade. Since media were sampled at different locations in the two sampling rounds, there is no way of knowing how the contaminated media have changed over time.
D. Physical and Other Hazards
To determine whether nearby residents are exposed to contaminants migrating from the site, PADOH evaluated the environmental and human components that lead to human exposure. An exposure pathway consists of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure, and an exposed population.
PADOH categorizes an exposure pathway as a completed or potential exposure pathway if the exposure pathway cannot be eliminated. In completed exposure pathways, the five elements exist, and exposure to contaminants occurred, is occurring, or will occur. In potential exposure pathways, however, at least one of the five elements is missing, but could exist. Potential exposure pathways indicate that exposure to a contaminant could have occurred, could be occurring, or could occur. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present.
A. Completed Exposure Pathways
Exposure to Contaminants Present on the Site
Evidence of off-road vehicle and foot traffic indicate that people use the site in ways that bring them into contact with contaminants present in ponded water, sediment, and exposed waste materials on the site. The people who frequent the site are exposed to the contaminants present in those media through direct skin contact, incidental ingestion, and inhalation of volatiles. Exposures are probably limited in duration, and the exposure levels are expected to vary from visit to visit. For instance, children who ride bicycles or play games on the site are likely to be exposed to higher levels of contaminants than the man dressed in business clothes seen during the site visit. However, none of the people that use the site are expected to be there over extended periods of time or every day. We do not know how many people frequent the site, but we do know that people have been exposed to contaminants and will continue to be exposed until access to the site is restricted.
According to the eyewitness accounts of former steel mill workers and local residents, Alan Wood Steel employees were exposed to hot mill wastes through direct contact when they worked on the leaking pipeline leading from the mill to the quarries. These exposures occurred many years ago, so no chemical analysis of that waste is available for further evaluation. The number of employees affected is, likewise, unknown.
Exposure Through Use of Contaminated Groundwater
Contaminated groundwater has traveled from quarries and other locations on site through fractured bedrock to at least one pumping (irrigation) well east of the site. We do not know if this well was ever used as a drinking water supply or for other domestic purposes. However, maintenance workers in the industrial/office complex who care for the grounds and maintain the well and the fountain and pond fed by the well are exposed to the contaminants present in the well water. The workers are exposed through direct skin contact with and incidental ingestion of contaminated water from the well and fountain. Also, volatile compounds released from the water are inhaled. These exposures will continue as long as contaminants are present in the water that is used.
B. Potential Exposure Pathways
Possible Exposures Through Use of Contaminated Groundwater
Though most residences and businesses in the area of the site rely on public water supplies currently unaffected by the site, there is apparently no restriction on the use of private wells. Therefore, a potential exposure pathway exists should wells be drilled downgradient of the site and contaminated water be used.
Large production wells, even in upgradient locations, could distort the groundwater flow regime and draw in contaminated water. That could result in contamination of well water now thought to be safe.
A. Toxicological Evaluation
To evaluate health effects, either a Minimum Risk Level (MRL) for contaminants developed by ATSDR, or a Reference Dose (RfD) developed by EPA has been used. The MRL is an estimate of daily exposure to a contaminant below which non-cancer, adverse health effects are unlikely to occur. The RfD is an estimate of a daily exposure (mg/kg/day) to the general public (including sensitive groups), which is likely to be without an appreciable risk of harmful effects during a lifetime exposure (chronic RfD) or exposure during a limited time interval (subchronic RfD).
People are not expected to be adversely affected by beryllium at the site even though they come into contact with it when they play, walk, or ride off-road vehicles on the site. However, repeated skin contact with beryllium may cause a skin condition that can appear as a rash or nodules to some chemically sensitive individuals (5).
People are exposed to beryllium when they come into contact with contaminated ponded water and sediments. Exposure occurs through dermal contact and through incidental ingestion of a little of the contaminated water or sediment. Most people are not expected to frequent the site enough to receive a dose of beryllium that would exceed the MRL; however, sensitized (allergic) people need only contact a small amount of beryllium to develop a skin rash (5). Although beryllium, when inhaled, is classified by EPA as a probable human carcinogen, people exposed at the site are not expected to have an increased risk of developing cancer because the amount of beryllium likely to be inhaled would be negligible (5).
People are not expected to be adversely affected by nickel at the site even though they come into contact with it when they play, walk, or ride off-road vehicles on the site. However, repeated skin contact with nickel may cause skin irritation to some chemically sensitive individuals (3).
People are exposed to nickel at the site when they come into contact with contaminated sediments. Exposure occurs through skin contact and through incidental ingestion of a little of the contaminated sediment. The amount of nickel found at the site is not a great deal higher than the amount normally found in soil throughout the United States. Most people are not expected to frequent the site enough to receive a dose of nickel that would exceed the MRL (3). People come into contact with nickel through touching money (coins), jewelry, buttons, and cooking utensils (3). Once a person is sensitized to nickel, that person only need to contact a small amount, such as that on site, to develop skin irritation.
Although nickel refinery dust and nickel subsulfide, when inhaled, are considered human carcinogens by EPA, people at the site would not inhale those types of nickel. Also, inhalation of any appreciable amount of nickel in any form at the site is unlikely. Therefore, people are not expected to have an increased risk of developing cancer because of contact with nickel at the site.
People are not expected to be adversely affected by cyanide at the site even though they come into contact with it when they play, walk, or ride off-road vehicles on the site. Although the effects of cyanide may vary from person-to-person, depending on age, general health, and other conditions such as family traits, brief exposures to levels of cyanide found at the site are not expected to produce symptoms associated with short-term exposure such as shortness of breath and convulsions (4). Short-term effects of low-level exposure disappear as cyanide is eliminated from the body (4).
Site visitors are likely to be exposed to cyanide by ingestion of and by skin contact with contaminated sediment. Incidental ingestion of cyanide-contaminated sediment, at the level detected on site, would not result in a dose that exceeds EPA's chronic RfD (4). Cyanide has not been shown to cause cancer in people or animals.
Tetrachloroethene and Benzene
Workers in the industrial park are not expected to have an increased risk of developing cancer even though they have been exposed to tetrachloroethene (PCE) and benzene. Benzene is classified as a human carcinogen by EPA, the National Toxicology Program of the U.S. Department of Health and Human Services (DHHS), and the International Agency for Research on Cancer (IARC) (8). PCE is reasonably anticipated to be a carcinogen by both NTP and IARC; however, that assumption is based on animal studies (8).
Levels of benzene that may cause non-cancerous effects to workers exposed periodically are not known. However, nothing was found in the literature to indicate that people exposed to the levels of benzene that workers in the industrial park would encounter have developed non-cancerous health effects (9). The workers are not expected to receive a dose of PCE found at levels in the well supplying the pond and fountain that would exceed EPA's chronic RfD (10). Therefore, exposure to PCE is not expected to cause non-cancerous health effects at the levels found in the well.
Workers are exposed to these chemicals as they perform maintenance activities involving the irrigation well and fountain. The workers are not expected to spend more than 10 hours a week each year working on the well, fountain, or pond. However, as with all carcinogens and possible carcinogens, exposure should be avoided whenever possible.
Polycyclic Aromatic Hydrocarbons (PAHs)
At present, no information is available from human studies to determine health effects resulting from exposure to specific levels of individual PAHs, although inhalation and skin exposure to mixtures containing PAHs has been associated with cancer in humans (6). We are unable to determine whether health effects will occur in site visitors who come in contact with PAHs.
People are exposed to the mixture of PAHs present on the site when they come into direct skin contact with exposed, contaminated wastes. Also, they may be exposed to small amounts of PAHs through ingestion. Some aromatic hydrocarbons can enter the body quickly by all routes of exposure, including inhalation of volatilized compounds (6).
B. Health Outcome Data Evaluation
The Crater Resources site is located in Upper Merion Township, Montgomery County. Twenty-one years of all cause mortality and cancer mortality (total cancer and eight cancer sites) were collected for Upper Merion Township (7). The 1980-1990 data were analyzed using Pennsylvania's 1984-1986 mortality experience as the standards and the 1990 Census population for age and sex.
The number of deaths from all causes and the number of cancer deaths were less than the expected number. There were 1,845 deaths observed in the 1980-1990 period, and 2,446 deaths would have been expected, producing a Standard Mortality Ratio (SMR) of 0.754. There were 510 cancer deaths observed with 632 cancer deaths expected (SMR 0.807). The individual cancer sites analyzed were: (1) buccal cavity and pharynx; (2) digestive system; (3) respiratory system; (4) bone, connective tissue, skin and breast; (5) genitourinary system; (6) other and unspecified sites; (7) leukemia; and (8) other lymphatic and hematopoietic tissues.
All eight cancer sites had fewer observed cancer deaths than would be expected. For the following three sites, the difference between observed deaths and expected deaths was significantly lower than expected: digestive system and peritoneum (SMR 0.774), respiratory system (SMR 0.834), and genitourinary system (SMR 0.689).
This mortality surveillance for Upper Merion Township indicates low mortality; however, this analysis is not sensitive enough to answer questions concerning health in the immediate vicinity of the NPL site.
C. Community Health Concerns Evaluation
We have addressed the community concerns about health as follows:
- Is the public water supply safe?
PADOH believes that the local public water supplies are safe for consumers. There is no evidence suggesting that the site has contaminated public wells or reservoirs.
- Was the soil under the pipeline that carried chemical waste to the quarries
Based upon telephone interviews with residents and former employees of the steel mill, pipeline leaks were common during the more than 60 years of operation. Leaks would continue for days, weeks, or months before being repaired, especially in harsh winter weather. It is almost certain, therefore, that soil along the pipeline route became contaminated with miscellaneous wastes.
- If the soil under the old pipeline was contaminated, where is the contamination today,
and what is the likelihood of exposure in light of recent earth moving and construction in
the community of Swedeland?
Only a comprehensive soil sampling and soil boring program along the pipeline can answer this question. Such a program, if initiated, should rely on personal interviews, aerial photographs, and historical documents from industry and governmental agencies. Once the contaminated soil is located and described (contaminants determined), potential exposure scenarios can be discussed and evaluated.